Tube spinning tool having rollers expanded radially by a conical spring pressed mandrel and a spring which releases the mandrel from the rollers



Dec. 24, 1957 H. L. BENJAMIN 2,817,385 TUBE SPINNING ToorJ HAVING RoLLERs EXPANDED PADIALLY BY A GGNICAL SPRING PREssED MANDREL ANDA SPRING wHIcH RELEASES THE MANDREL. FROM THE RoLLERs Filed oct. 9, 195s l f Z BY 2'?. Y' EHSATTOHNEQ United States Pate-nt iC) "i TUBE SPINNING TOOL HAVING `ROLLERS EX- `PANDED RADIALLY BY A CONICAL SPRING 'PRESSED MANDREL` AND A SPRING WHICH RELEASES THE MANDREL FROM THE ROLLERS Harry L. Benjamin, Dayton, Ohio, assigner to United llcraft Products, Inc., Dayton, Ohio, a corporation of Application October 9, 1953, Serial No. 385,131

3 Claims. (Cl. 153-82) This .invention relates to tools for installing tubes in Vsupporting plates, and has especial although lnot 'limited application to the art of securing thin walled heat exchange tubes in openings provided therefor in -header plates. The invention is useful, for example, inthe fabrication of oil cooling devices for aircraft wherein thin walled, hollow tubes are supported in adjacent parallel relation between supporting end plates for the flow of a `first fluid through the tubes and ow of a second `fluid around `and between the tubes. It is required that `the tube ends have a tight fitting mounting in `the end plates, effective to prevent leakage and sulciently strong to reu sist the stresses of Huid pressure and of Vibration.

The invention is particularly concerned with that class `of tool having a working end to enter the tube and to Vapply a radial, outwardly directed force which expands the tube end into intimate contact with the surrounding wall of the plate opening, according `to a metal Working concept .sometimes called spinning.

An object of the invention is to enable the duration and `extent of a tube securing operation to be predetermined in such manner as `to avoid weakening of the joint proiduced.

Another object of the invention is substantially to eliminate the need for special operator skill in the securing of a tube end, it being proposed that the operator `need merely bring the tool to a working position with the tool itself thereafter operating automatically to effect and to discontinue the spinning operation.

A further object of the invention is to obviate bowing .of the tubes under developed pressures of the tube securrug operation. i

Still another object of the invention is to achieve a uniformity of results in the installation of multiple tubes.

A still furthr object of the invention is to present a tool which can be used in multiple form in a drill press or like machine for the simultaneous securing of a plurality of tube ends, it being a further object in this connection independently to control the several tools so that their operation may be separately and independently discontinued as required.

Other objects and structural details of the invention will appear from the following description `when read in connection with the accompanying drawing, wherein:

Fig. l is a View in side elevation of a tool in accord ance with the illustrated embodiment of `the invention, shown inserted in a tube end preparatory to starting the spinning operation;

` Fig. 2 is a view of the tool'in longitudinal section, with the parts being shown in the same position as Fig. '1; and

Fig. `3 is a fragmentary enlarged view of the tip of the tool, shown inserted in a tube in the same position as Fig. 1.

Referring to the drawings, a fragment o f a plate is shown, having an opening 11 receiving the end of a Atube 12; the device of the instant invention operating from 70 2,817,385 yPatented Dec. 24, 1957 ICC ing. The device is disclosed as constructed and `arranged for installing thin walled heat `exchange tubes rin header plates, `the resulting structure having utility as the core .of oil `cooling and like (devices.

The tool includes a cylindrical body 413 formedwith a through slot 14 and having on its one end a projecting stem 15 in screw threaded engagement with a spindle eX- tension 16. The latter has a shank 17 adapted lto be received in the head of a drill press or the like whereby the :body 13 `may be moved toward and from the plate `10 in an axial sense and also be rotated in `forward and reverse directions. A commutator assembly '18 is rmounted on the spindle extension '16 serving a purpose in controlling the bodily movements `of the device which it is unnecessary hereto understand.

The opposite `end `of the body 13 is formed with a`=coun terbore 19 internally threaded vto receive a bushing 251, a lock nut 22 serving to hold `the body 13 and bushing 21 -in yset `positions of adjustment. The bushing 21 `also is internally threaded and receives `aisecond bushing 23, held with respect to `the first bushing by a lock nut 24. The `bushing 23 is formed with a transverse web 25 providing a bearing for a tapered mandrel Y26, the small .end of which projects through and beyond the bushing 23. The opposite end of the mandrel l26 is formed las a cylindrical portion `2'7 having `a sliding t in a bore 28 in the `body 13, xsuch portion 27 being connected by a vstep down shoulder 29 `to a somewhat smaller intermediate cylindrical portion 31. A washer 32 surrounds the portion 31 and is urged `by a compression spring 33 to a seat in the bottom of counterbore 19, the spring 33 being based on the web 25. The inner extremity of the cylindrical portion 27 projects into a counterbore 34 where it is acted on by a disc 35 and compression spring 36 in a manner tending to resist inward axial motion of the mandrel 26 relatively to the body 13.

The outer extremity `of the mandrel 26 is of a size `for free entry `into the end of the tube 12 and has a wing formation 37 serving to retain on the mandrel a `sleeve assembly 38. The latter includes an inner sleeve 39 and an outer sleeve 41 of a 4size to abut the ,end of the tube. The sleeves 39 and 41 are inter-connected through a bearing 42. The sleeve 39 has a projecting portion 43 formed with a circumferential `series of approximately radial inclined slots 44 in which are `installed cylindrical rollers 45. As may be seen, the construction and arrangement of parts is such that a relative axial motion of the mandrel and sleeve assembly will when accomplished in one sense press the rollers 45 outward into Contact with the tube and when accomplished in an opposed sense relieve such pressure. Still further, on account of the angular disposition o f the rollers 45, relative rotation of the mandrel 26 in one direction will serve to draw the mandrel axially with respect to the sleeve assembly 3S, with `the rollers 45 acting in effect `as screw threads to induce such motion. It will be understood, in this connection, that the rollers 45 are mounted inthe slots 44 with some freedom of lateral motion. Thus, upon a reversal `of the direction of rotation of the mandrel, the rollers 45' may move to release the mandrel.

A compression spring 46 is interposed between the sleeve assembly 38 and the web 25 and tends to extend the sleeve assembly outwardly Valong the mandrel 26,. v,A transverse pin 47 is passed through the cylindrical portion 27 of the mandrel and its ends lie in the slot 14. The mandrel 26 thus is connected to .the body 13 for .unison rotary movement but is permitted a relative longitudinal movement.

Normally, the mandrel v26 occupies a. position relatively projected with respect to the position shown in Fig. 2. Thus the shoulder 29 on the mandrel normally rests on the washer 32 and the disc 35 is in the bottom of counterbore 34. The mandrel is in eect stabilized by or balanced between the springs 33 and 36. Further, under the influence of spring 46, the sleeve assembly 33 is normally relatively extended, with the sleeve portion i3 substantially engaging the winged formation 37.

In the securing of a tube end to the header plate 10, the tip 37 of the mandrel is inserted in the tube and is followed therein by the sleeve portion 43, it being understood that this is done by bodily advancing the device upon the work. The entering motion of the sleeve assembly is limited by engagement of the sleeve 4l with the end of the tube or with the plate and continued motion of the body 13 and mandrel 26 is effected relatively to the sleeve assembly 38. As a result, the rollers 45 move outward into contact with the wall of the tube and are in effect wedged there interrupting the relative aXial motion of the mandrel. lf now the body f3 is continued to be moved toward the work, it advances relatively to the mandrel 26 resulting in a compressing of the spring 36. There may be provided a fixed stop for the body `13, against which the operator may move the body.

. It is not required, in this connection, that advance of the body perform any function in the actual securing of the tube, but merely that it properly locate the parts for such operation and place the spring 3S under corny pression or to tension it. Fig. 2 illustrates the device as it may appear when the operator has brought the body to such fixed stop. Rotation of the body 13 and, therefore, of the mandrel 26 may be continuous or may be initiated when the parts reach the Fig. 2 position. In such position, the spring 36 urges the mandrel outward wedging engagement with the rollers 45. Thus rotation of the mandrel induces a continued axially extending motion of the mandrel under the influence of the spring 36 and of the rollers 45 which exert a drawing effect on the mandrel, as before described. Accordingly, the mandrel 26 travels axially into the tube l2 and further expands the series of rollers 45 with a consequent deforming of the material of the tube into an intimate contacting relation with the wall of opening ll. As the mandrel 26 travels under the above described inuences, the disc 35 returns to the bottom of the counterbore 34 and the shoulder .29 re-engages the washer 32, with continued `travel of the mandrel displacing the washer 32 and placing the spring 33 under compression. Now when a sufficient deforming or spinning of the tube end has taken place, the direction of rotation of the mandrel is reversed. The effect, as previously noted, is to release the mandrel from the rollers 45 whereupon the spring 33 immediately returns the mandrel to a stabilized position between the springs 33 and 36. The body 13 then may be returned to its starting position, lifting the mandrel and sleeve assembly 38 out of the finished tube.

The duration of the spinning operation is in the illustrated instance dimensionally controlled. Thus a switch and switch operating assembly d8 is mounted on the body 13 and controlled by the pin LS7. Such assembly includes a micro-switch i9 suitably connected in an electric cirg cuit operable to stop the rotation of the body f3. The Lswitch i9 is operated by an arm Sli connected to a car- -riage 52 which includes fixed abutment portions 53 and 54 engaged alternately by the pin 47. The device is animes individually controlled so that multiple spinning devices may be mounted for simultaneous operation in a single press. Thus the several devices may be lowered as a unit against a common stop and thereafter each device performs its spinning function independently of one an- -other. As each completes its respective work it is stopped, 1 .x

into tight fitting position in openings provided therefor in header plates, includng a body subject to longitudinal and rotary motions, a mandrel supported by said body in concentric relation thereto and for unison rotary and relative longitudinal motions, said mandrel having a projecting tapered end adapted freely to enter the end of a tube, a sleeve slidably mounted on the projecting end of said mandrel and having a first portion adapted to enter the tube and a second portion adapted to limit against the end of the tube, rollers carried by the said first portion of said sleeve and movable radially outward by said mandrel in response to an axially traveling motion of said mandrel into said tube relatively to said sleeve, said rollers being angularly disposed in such wise as to draw said mandrel into the tube in response to rotation thereof in one direction, a spring interposed between said body and said mandrel and tensioned by a continued longitudinal motion of said body in a direction entering said mandrel in the tube beyond that required to engage said rollers with the inner surface of the tube, and another spring tensioned by an axial motion of said mandrel relatively to said bodyy under infiuence of said rollers and effective to move said mandrel in a withdrawing direction in response to rotation of said mandrel in the opposite direction.

2. A device for installing the ends of hollow tubes into tight fitting position in openings provided therefor in header plates including'a body subject to rotary and longitudinal motions, a mandrel supported by said body for relative longitudinal unison rotary motions, said mandrel having a projecting tapered end adapted freely to enter the end of a tube, a sleeve slidably mounted on the projecting end of said mandrel and having a first portion adapted to enter the tube, and a second portion adapted to limit against the end of the tube, an-gularly disposed rollers carried by the said first portion of said sleeve, said rollers being displaced radially outward into contact with the inner tube surface by a relative longitudinal tube entering motion of said mandrel and said rollers further tending to draw said mandrel further into the tube in response to rotation of the mandrel in one direction following contact of the rollers with the tube surface, a spring tending to inhibit relative longitudinal motion of said body and mandrel, and tensioned by longitudinal motion of said body beyond that required to engage said rollers with the tube surface, and another spring tensioned by a longitudinal motion of said mandrel under influence of said rollers for releasing said mandrel from said rollers in response to rotation of said mandrel in the opposite direction.

3. A device for installing the ends of hollow tubes into tight fitting position in openings provided therefor in header plates, including a tapered mandrel, the small end thereof being adapted freely to enter the end of a tube, a sleeve slidably mounted on the mandrel and having a first portion adapted to enter the tube end and a second portion adapted to limit against the tube end, rollers carried. by the said first portion and displaced radially outward into contact with the inner surface of the tube by an initial inward motion of the mandrel relatively to said sleeve, said rollers being angularly disposed to draw said mandrel further into the tube in response to rotation of said mandrel in one direction, a rotatable and longitudinally movable body carrying said mandrel, said mandrel being movable relatively to said body in a longitudinal sense, a spring inhibiting relative longitudinal motion of said mandrel and tensioned by an overtravel of said body beyond that required to effect the said initial inward motion of said mandrel, and a further spring tensioned by an inward motion of said mandrel under inliuence of said rollers for releasing said mandrel from said rollers in response to rotation of said mandrel in the opposite direction.

'(Reflerences on following page) UNITED STATES PATENTS 1,111,125 Baumann Sept. 22, 1914 1,410,464 Gallon Mar. 21, 1922 1,506,988 Mireld Sept. 2, 1924 6 Meunier Dec. 17, 1929 Fisher Aug. 15, 1944 Gilman May 31, 1949 Fitzgerald Feb. 27, 1951 Knowlton Mar. 27, 1951 

